package Action.letcode;

/**
 * Created by zll on 2017/9/4 0004.
 * Say you have an array for which the ith element is the price of a given stock on day i.
 * <p>
 * If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit.
 * <p>
 * Example 1:
 * Input: [7, 1, 5, 3, 6, 4]
 * Output: 5
 * <p>
 * max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price)
 * Example 2:
 * Input: [7, 6, 4, 3, 1]
 * Output: 0
 * <p>
 * In this case, no transaction is done, i.e. max profit = 0.
 * <p>
 * 求数组中后面减去前面最大的值
 */
public class MaxProfit {
    public int maxProfit(int[] prices) {
        int max = 0;
        for (int i = 0; i < prices.length - 1; i++) {
            for (int j = i + 1; j < prices.length; j++) {
                max = Math.max(prices[j] - prices[i], max);
            }
        }
        return max;
    }
}
